1. Field of the Invention
This invention relates to a tandem master cylinder, and more particularly to a tandem master cylinder with a liquid pressure control valve (proportioning valve) integrally constructed therein for preventing automobile rear wheels being locked early.
2. Description of the Prior Art
An automobile brake device with two separate liquid pressure brake systems for ensuring safety at a brake failure or trouble is often used these days as a safety means. When brake action is applied to an automobile, load distribution between front wheels and rear wheels is changed, so that the rear wheel load becomes much smaller than the front wheel load. Thus, if the liquid pressure for braking applied to the rear wheels is the same as that applied to the front wheels, the rear wheels tend to be locked before the front wheels for causing rear wheel skidding or the so-called "rear-end swaying" which is highly dangerous. Accordingly, most of the aforesaid two-system safe brake devices are provided with such a liquid pressure control valve disposed in rear wheel brake systems thereof, which valve restricts the rear wheel brake liquid pressure from rising in excess of a certain liquid pressure level. The liquid pressure control valve to be disposed in the rear wheel brake system has shortcomings in that space for mounting such valve is difficult to secure, that number of parts forming the brake system tends to become too large, and that piping workability is considerably deteriorated.